The present invention relates to an electronic device which comprises a heat generating element in a housing, such as a power source device, a timer, or a temperature adjuster, also to a panel device in which plural such electronic devices (a concept including all such as an electric apparatus and an electronic apparatus) are usually accommodated in a same panel with the object of control, monitor, or the like, and also to a support rail which is used for supporting such an electronic device in such a panel in a juxtaposed state, such as a DIN rail.
As an electronic device which comprises a heat generating element in a housing, for example, known is a power source device such as a switching power source. The power source device incorporates a heat generating element such as a switching transistor or a rectifying diode in a housing. In such a power source device of the conventional art, a housing is configured by a material which is inferior in heat radiating property than a metal, such as a resin. The device incorporates a heat generating element and a heat radiating member which radiates heat generated by the heat generating element, in the housing. The heat radiated from the heat radiating member is discharged to the outside through a large number of heat radiating slit holes which are formed in a side portion of the housing.
In a power source device of another conventional art example, a housing may be configured by a material which is superior in heat radiating property, such as a metal. A heat radiating member is placed in the housing, and heat from the heat radiating member is conducted also to the housing, thereby improving the heat radiation efficiency.
(Technical Problems that the Invention is to Solve)
In the former power source device, however, the periphery of the heat radiating member is covered by the housing made of a resin which is a material having inferior heat radiating properties, and hence there is a problem in that, even when many heat radiating slit holes are formed in the housing, heat of the heat radiating member is hardly dissipated to the outside of the housing, thereby impairing the heat radiating properties of the device.
By contrast, in the latter power source device, the side portion of the housing is configured by a metal which is a material having superior heat radiating properties. Therefore, the device is superior in heat radiating property than the former device. Since the housing material is a metal, however, an insulation distance from the housing must be set to be relatively large so as to prevent an electronic component in the housing from being in contact with the housing. Therefore, the latter power source device has a problem in that, even in the case of a power source of a small capacity, the size of the housing is large and hence the device cannot be made compact and is heavy, with the result that it is very difficult to handle the device.
It is a common object of the invention to provide an electronic device in which, even when a housing is configured by a material such as a resin which is inferior in heat radiating property than a metal, heat generated by a heat generating element in the housing can be efficiently discharged to the outside of the housing, and which therefore has excellent heat radiating properties.
(Solving Method and Effects Superior than Conventional Art)
In order to attain the object, a first feature of the invention is an electronic device comprising: a housing; a first metal member having portions which face to an inside and an outside of the housing, respectively, and attached directly or indirectly to the housing; and a heat generating element which is attached to the portion of the first metal member, the portion facing the inside of the housing.
According to the first feature, even when the housing is configured by a resin which is inferior in heat radiating property, for example, heat generated by the heat generating element attached to the portion of the first metal member facing the inside of the housing is easily radiated to the outside of the housing through the portion of the first metal member facing the outside of the housing. Therefore, the electronic device has excellent heat radiating properties.
A second feature of the invention is an electronic device comprising: a housing; a first metal member facing an outside of the housing; a second metal member which is formed integrally with the first metal member, or coupled to the first metal member directly or via another metal member, and which is located in the housing; and a heat generating element which is attached to the second metal member.
According to the second feature, even when the housing is configured by a resin which is inferior in heat radiating property, for example, heat generated by the heat generating element attached to the second metal member is conducted from the second metal member to the first metal member. Since the first metal member faces to the outside of the housing, the generated heat is easily radiated to the outside of the housing. Therefore, the electronic device has excellent heat radiating properties.
A third feature of the invention is an electronic device in which the electronic device of the second feature is configured so that the second metal member is elongated into the housing, and the heat generating element is attached to an elongated portion.
According to the third feature, when the elongated portion is arbitrarily elongated, the attaching position of the heat generating element can be freely set, so that an electronic component in the housing can be placed in a very easy manner or the degree of freedom in design is improved. On the other hand, since the elongated portion is coupled to the first metal member facing the outside of the housing, heat generated by the heat generating element can be easily radiated to the outside. Therefore, the electronic device has excellent heat radiating properties.
A fourth feature of the invention is an electronic device in which the electronic device of any one of the first to third features is configured so that a rear portion of the housing is opened, and the rear opening of the housing is covered with the first metal member.
According to the fourth feature, a metal member having a large area can be used as the first metal member, and hence heat generated by the heat generating element can be easily conducted to the outside. Therefore, an electronic device of further excellent heat radiating properties can be obtained.
A fifth feature is an electronic device in which the electronic device of any one of the first to fourth features is configured so that a support member attaching portion is disposed in a portion of the first metal member facing the outside of the housing.
According to the fifth feature, since the support member attaching portion is disposed in a portion of the first metal member facing the outside of the housing, the device can be used for attaching a support member.
A sixth feature is an electronic device in which the electronic device of the fifth feature is configured so that the support member attaching portion can be grounded through a support member attached to the support member attaching portion.
According to the sixth feature, when the device is attached to the support member, the member can perform a shielding function against electrical noises generated from an internal electronic component.
A seventh feature is an electronic device having: a housing in which a rear portion is opened, and which has a terminal block attaching hole in a front side; and device configuring members which can be incorporated into the housing through the housing rear opening, the device configuring members including at least: a circuit board on which the terminal block is mounted; a heat generating element; and a metal member, the circuit board being accommodated in the housing so that, under the incorporated state, the terminal block positionally corresponds to the terminal block attaching hole in the front side of the housing, the metal member serving under the incorporated state as a covering member for the housing rear opening, the heat generating element being attached to at least a portion of the metal member which is located in the housing.
According to the seventh feature, in addition to the effect of heat radiating properties due to the metal member, assembling of the device is completed only by accommodating the device configuring member through the housing rear opening. Therefore, assembling is easy, and also the time period required for assembling is shortened. Since the metal member serves as a covering member for the rear opening of the housing, moreover, the device itself can be made compact.
An eighth feature of the invention is an electronic device in which the electronic device of the seventh feature is configured so that, under an integrated state in which the circuit board is attached to the metal member, the device configuring member can be accommodated into the housing through the housing rear opening.
According to the eighth feature, assembling of the device configuring members themselves has been already completed, and hence assembling of the device configuring members into the housing is further simplified.
A ninth feature is an electronic device having: a housing in which a rear portion is opened, and which has a terminal block attaching hole in a front side; and device configuring members which can be incorporated into the housing through the housing rear opening, the device configuring members including at least: a circuit board on which the terminal block is mounted; a heat generating element; and first and second metal members, the circuit board being accommodated in the housing so that, under the incorporated state, the terminal block positionally corresponds to the terminal block attaching hole in the front side of the housing, the first metal member serving under the incorporated state as a covering member for the housing rear opening, the second metal member being formed integrally with the first metal member, or coupled to the first metal member directly or via another metal member, the heat generating element being attached to the second metal member, the second metal member being located in the housing under the incorporated state.
According to the ninth feature, in addition to the effect of heat radiating properties due to the metal members, assembling of the power source device is completed only by accommodating the device configuring members through the housing rear opening. Therefore, assembling is easy, and also the time period required for assembling is shortened. Since the first metal member serves as a covering member for the rear opening of the housing, moreover, the device itself can be made compact.
A tenth feature of the invention is an electronic device in which the electronic device of the ninth feature is configured so that, under an integrated state in which the circuit board is attached to at least one of the first or second metal member, the device configuring members can be accommodated into the housing through the housing rear opening.
According to the tenth feature, assembling of the device configuring members themselves has been already completed, and hence assembling of the device configuring members into the housing is further simplified.
An eleventh feature is an electronic device in which the electronic device of the ninth or tenth feature is configured so that the circuit board includes first and second circuit boards which are respectively located and accommodated in front and rear sides of the housing so as to be separated from each other in parallel with or in substantially parallel with each other, the terminal block is mounted on the first circuit board, an electronic component constituting a noise filter circuit is mounted on the first circuit board, and an electronic component generating electrical noises is mounted on the second circuit board.
According to the eleventh feature, the first circuit board and the second circuit board are separated by a distance in the housing. Even when noises generated from the electric noise generating electronic component mounted on the second circuit board try to be transmitted through the air, therefore, the noises are blocked by the first circuit board. As a result, the possibility that the noises enter the terminal block mounted on the first circuit board is lowered. Therefore, the electronic device has excellent noise resistance.
A twelfth feature is an electronic device which has a heat generating element in a housing, and in which a rear portion of the housing is supported by a support rail made of a metal, wherein a heat generating element attaching member is placed so as to face a rear opening of the housing, the heat generating element attaching member or the heat generating element is enabled to be directly or indirectly in contact with the support rail under a state where the support rail is attached to the opening, and the contact allows heat generated by the heat generating element to be radiated to a side of the support rail.
According to the twelfth feature, heat radiation can be performed through the support rail. Even when the housing is configured by a material such as a resin which is inferior in heat radiating property than a metal, therefore, heat generated by the heat generating element in the housing can be efficiently discharged to the outside of the housing, and the electronic device has excellent noise resistance. Furthermore, the support rail is sufficiently wide and long, and has sufficient heat radiating properties. Consequently, it is not required to dispose a heat radiating plate or the like in the housing, and hence the device can be further miniaturized.
A thirteenth feature is a panel device in which one or more of the electronic device of claim 12 is accommodated in a panel under a state where the device is supported by a support rail, the support rail has a cavity, and a heat discharging gas is enabled to be introduced from an outside of the panel into the cavity and then discharged to the outside of the panel.
According to the thirteenth feature, when the support rail is passed through the panel, the cavity allows, for example, the outside air serving as the heat discharging gas to be introduced from an inlet on one side of the cavity of the support rail, and the outside air is discharged from an outlet on another side of the cavity. In the discharge of the outside air, heat of the heat generating element in the electronic device is conducted to the air in the cavity of the support rail, and the cavity air to which the heat is conducted is discharged to the outside. Therefore, the heat radiation efficiency with respect to the head generated by the heat generating element is excellent. Since it is not required to form a suction port in the panel, the air itself in the panel is isolated from the outside. Unlike the conventional art, consequently, air is not sucked together with dust through a suction port into the panel, and the air in the panel is not contaminated. Moreover, the support rail can be easily cooled, and hence its heat radiation efficiency can be enhanced more easily. Since a suction port is made unnecessary, the panel can be hermetically sealed so as to attain good waterproofness.
A fourteenth feature is a support rail for supporting an electronic device which has a heat generating element inside a housing, wherein the support rail has a cavity which passes through the support rail from one end side to another end side, and a structure in which heat conducted from the heat generating element is discharged by a gas that flows into from the one end side of the cavity and then flows out from the other end side.
According to the fourteenth feature, a structure is obtained in which heat conducted from the heat generating element is discharged via the cavity which passes through from one end side to the other end side, by a gas which flows into from the one end side of the cavity and then flows out from the other end side. Therefore, it is possible to attain the same effects as the panel device which uses the support rail.
A fifteenth feature is a support rail in which the support rail of the fourteenth feature is configured so that heat radiating fins are disposed in the cavity.
According to the fifteenth feature, since heat radiating fins are disposed in the cavity, it is possible to attain the effect that the heat radiation efficiency can be further enhanced.
In the metal members described above, a metal is used as a constituting material. The metal members are not restricted to those which are thoroughly configured by a metal. Also a member which partly contains a material other than a metal, or that which is integrated or connected with a material other than a metal is included in the invention.
The attachment of the heat generating element to the second metal member has a broad meaning including all cases where a portion of the heat generating element other than leads is attached by screws, bonded by using an adhesive agent, or closely contacted by applying a pressing force by using a plate spring, and where the heat generating element is attached to the second metal member by other means in a manner that heat radiation is enabled.